1. Field of the Invention
This invention relates generally to inflatable motor vehicle occupant restraint systems, and more particularly, to an improved seat mounted module assembly for a vehicle supplemental inflatable restraint system which provides side impact protection.
2. Background Information
A significant percentage of occupant injuries are caused by side impact collisions. Conventional air bag modules have been utilized in frontal collisions in order to minimize occupant injuries. A typical air bag module has a housing, an inflator affixed to the housing, and an air cushion or air bag that is part of a restraint module. A crash sensor is used to sense a vehicle collision which triggers the inflator to release inflation gases and inflate the air bag. Vehicle air bags have been shown to provide a significant overall decrease in occupant injuries during frontal impacts. In view of this, recent attempts have been made to incorporate side impact air bags into vehicles in order to produce a similar reduction in occupant injury resulting from side impacts.
One type of side impact module assembly is mounted within a vehicle door in combination with a side impact sensor. The air bag is retained behind a deployment panel that opens to release the air bag during deployment. However, one problem with this type of side impact module results from the fact that different size occupants are present in the vehicle and the seats can be adjusted to various positions within the vehicle. For example, a large occupant will move a seat on the adjustable seat track to a rearmost position whereas a small occupant will move the seat to a fully forward position. Therefore, a larger air bag must be deployed from the vehicle door in order to cover the entire range of occupant seating positions and occupant sizes.
A second type of side impact air bag module is mounted to the vehicle's B-pillar or lock pillar. However, this implementation still suffers from the same problems inherent with mounting the module to a vehicle door; namely, the larger air bag must be utilized in order to cover the entire range of position of variously sized occupants.
A third type of side impact air bag module is mounted to a vehicle seat. By mounting the air bag module to a seat, which moves with the occupant, the air bag, can be deployed to a same position relative to the occupant regardless of the size and seating position of the occupant. Typically, a side impact module similar to those used for a front collision passenger air bag module are incorporated within a vehicle seat. The air bag, must emerge from the seat by tearing the seat trim, which is then damaged and probably irrepairable.
In addition to the foregoing, there is a continuing need to provide ease of assembly of the module as well as convenient mounting to the vehicle. The above-mentioned modules are mounted inside various vehicle components and upon deployment, the air bag, breaks through covering trim material or panels. In order to improve case of assembly, the side impact module of the subject invention is configured to be mounted externally on the outer surface of a vehicle seat. Since the module is external, it is in plain view. One reason for wanting a visible side impact module is so the occupant knows it is there and does not obstruct it. Further, assembly and replacement is made easier with an externally mounted design since it is not buried in the seat, thus allowing servicing the module without tearing, the seat apart. A visible module is also a good advertising point for the vehicle manufacturer, since it reminds the consumer of the presence of this feature on the automobile.
In order to address the design issues presented above, it is an object of the present invention to provide an improved side impact air bag module for a vehicle supplemental inflatable restraint system which is externally mounted to a vehicle seat.